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The Elephant's Foot is a deadly reminder of the Chernobyl disaster. This highly radioactive solid material is made up of melted nuclear fuel, concrete, and other materials present in the reactor at the time of the explosion. The Elephant's Foot is considered the most radioactive object on Earth and is so dangerous that exposure to it for even a few minutes can be lethal. Its environmental and human health impact is still being studied and monitored today.

Keep reading to learn about Earth's most radioactive object and its environmental impact.

Scenes of Chernobyl nuclear accident
Scenes of Chernobyl (abandoned building, stairwell, former entrance to amuzment park, abandoned school)

The Disaster

The Chernobyl disaster of 1986 was the most catastrophic nuclear accident in history. It happened at the Chernobyl Nuclear Power Plant in Pripyat, Ukraine, and was caused by a combination of human error and design flaws in the Soviet RBMK-1000 reactor. During a routine stress test, control rods were removed, and power levels were increased to compensate for low reactivity caused by xenon poisoning. However, the RBMK-1000 reactor had a positive void coefficient at low power levels, which caused a rapid increase in power output and led to the fuel rods cracking and the cooling water turning to steam. The explosion was so powerful that it blew a 1,000-ton fastening plate through the roof of the building, causing the biological shield to lift and allowing lava to melt through the core. The resulting nuclear fission products were spread into the atmosphere and Eastern Europe for nine days, causing widespread contamination and long-term health effects.

One of the most dangerous consequences of the disaster was the formation of the "elephant's foot," a mass of highly radioactive material that solidified in the reactor and remained a hazard to this day.

Melted Corium, Chernobylite, Elephants Foot Chernobyl

During the Chernobyl disaster, the reactor rods reached temperatures between 3,200 and 4,800 degrees (1,660°C and 2,600°C), causing them to crack and melt into a lava-like substance at the bottom of the reactor. This substance, known as Corium or Chernobylite, was made up of not only the uranium fuel rods but also graphite moderators, boron control rods, and surrounding sand and concrete. The extreme heat caused the Corium to melt through steel beams and other structures before eventually cooling down and solidifying into a silicate material containing up to 10% uranium.

The most infamous example of Corium is the "elephant's foot" located beneath reactor number four at Chernobyl. This mixture of uranium, plutonium, fission products, silicon dioxide, and other materials absorbed during the core's destruction is only one meter in size but weighs an estimated two metric tons. Despite containing only 10% uranium, it releases a deadly dose of 10,000 roentgens per hour, which would kill a human within 300 seconds if they were standing within three feet of it.

When viewing photos of corium, a noticeable blur can be seen in the film due to the high energy alpha particles hitting the film and affecting its quality (see below). The extreme radiation levels in the area make it impossible for any living cell, no matter how small, to survive.

Elephants foot Chernobyl
Elephants foot Chernobyl (right) resembles an elephant's foot (left)

Radiation Levels: How Dangerous is The Elephant's Foot?

In 1986 the Elephant's Foot emitted radiation levels of up to 10,000 roentgens per hour, making it the most radioactive object on Earth. To put this into perspective, a lethal dose of radiation for humans is around 500 roentgens. Anyone who approached would have received a fatal dose in under a minute. In the first seconds of exposure, they would experience dizziness and fatigue, followed by vomiting and diarrhea. Soon after, the body cells would begin to hemorrhage.

Despite being discovered over 30 years ago, the Elephant's Foot remains highly radioactive and dangerous. Its high radiation levels make it impossible for humans to approach without proper protective gear, and even then, exposure should be limited. The Elephant's Foot continues to pose a threat to the environment and surrounding areas, and efforts are ongoing to contain and monitor its radiation levels. It serves as a stark reminder of the devastating impact of nuclear disasters and the importance of safety measures in the nuclear industry.

Effects of the Elephant's Foot on the Environment

The Chernobyl nuclear disaster released 100 times more radioactive material than the atomic bomb dropped on Hiroshima. This has significantly impacted the environment surrounding the reactor site and the entire region. The high radiation levels emitted by elephants foot have contaminated the soil and water in the area, making it difficult for plants and animals to survive. The radiation has also affected the genetic makeup of organisms in the area, leading to mutations and abnormalities. The long-term effects of the Elephant's Foot on the environment are still being studied, but it is clear that the disaster has had a lasting impact on the surrounding ecosystem.

How is the Elephant's Foot Being Monitored and Contained?

After the Chernobyl disaster, a massive effort was made to contain the spread of radioactive materials. Despite attempts to drop sand, boron, and lead in the core to absorb neutrons, the materials continued to spread. However, the ongoing fires were eventually stopped, and a "sarcophagus" was built to prevent further contamination. This structure, made of 400,000 cubic meters of reinforced concrete, contained 16 tons of uranium and 30 tons of radioactive dust. Its purpose was to prevent the release of these materials into the atmosphere and protect the surrounding environment.

Today a "New Safe Confinement" megaproject surrounds the reactor building. It was designed with the primary goal of confining the reactor core for the next 100 years. The Elephant's Foot Corium is being monitored and contained by scientists and engineers. The object is encased in a concrete sarcophagus built to prevent further radiation leaks. The sarcophagus is regularly monitored for any signs of deterioration or damage, and the surrounding area is also monitored for radiation levels. The team is also developing new technologies to safely remove the Elephant's Foot and other radioactive materials from the site. However, the high radiation levels make this a difficult and dangerous task, and it may be many years before a solution is found.

New Safe Confinement of chernobyl
Abandoned buildings at Chernobyl, New Safe Confinement seen in background, forming a dome over elephants foot and reactor 4.


Despite being discovered over 30 years ago, elephants foot Chernobyl remains one of the most radioactive objects on Earth and extremely dangerous to approach, even with protective gear. Elephants Foot remains a threat to the environment and surrounding areas, and efforts are ongoing to contain and monitor its radiation levels. Its high levels of radiation serve as a reminder of the devastating impact of nuclear disasters and the importance of safety measures in the nuclear industry.

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  1. The Most Radioactive Object on Earth


  1. "Report on the Accident at the Chernobyl Nuclear Power Station," U.S. Nuclear Regulatory Commission, NUREG-1250, January 1987.

  2. "Sources and Effects of Ionizing Radiation, UNSCEAR 2000 Report to the General Assembly, Vol II," United Nations, 2008, Annex J: Exposures and Effects of the Chernobyl Accident.

  3. S. A. Bogatov et al., "Formation and Spread of Chernobyl Lavas," Radiochemistry 50, 650 (2009).

  4. B. E. Burakov et al., "The Behavior of Nuclear Fuel in First Days of the Chernobyl Accident," MRS Proceedings 465, 1297 (1996).

  5. D. Sim, "Chernobyl: Huge Sliding Arch to Block Radiation Is Nearing Completion 30 Years After Nuclear Disaster," International Business Times, 26 Apr 16.

  6. "Chernobyl's New Safe Confinement.” September 2, 2020.

  7. "Contract for early Chernobyl dismantling work signed: Waste & Recycling - World Nuclear News.” September 2, 2020.

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